Spider Star
The human colony on the planet Argo has long explored and exploited the technology left behind by an extinct alien race. But then an archaeology team accidentally activates a terrible weapon...
Read More.Praise for Star Dragon
"Seldom does a storytelling talent come along as potent and fully mature as Mike Brotherton. His complex characters take you on a voyage that is both fiercely credible and astonishingly imaginative. This is Science Fiction."
-- David Brin"Star Dragon is terrific fare, offering readers a fusion of hard science and grand adventure."
-- Locus Magazine"Star Dragon is steeped in cosmology, the physics of interstellar travel, exobiology, artificial intelligence, bioscience. Brotherton, author of many scientific articles in refereed journals, has written a dramatic, provocative, utterly convincing hard science sf novel that includes an ironic twist that fans will love."
-- Booklist starred review"Readers hungry for the thought-provoking extrapolation and rigorous technical detail of old-fashioned hard SF are sure to enjoy astronomer Brotherton's first novel."
-- Publishers Weekly"Mike Brotherton, himself a trained astrophysicist, combines the technical acuity and ingenuity of Robert Forward with the ironic, postmodern stance and style of M. John Harrison. In this, his debut novel, those twin talents unite to produce a work that is involving on any number of levels. It's just about all you could ask for in a hardcore SF adventure."
-- Paul di Fillippo, SCI-FI.COM
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The Difference Between Spiral Structure in Galaxies and in Hurricanes
April 26th, 2008
I was giving an astronomy talk at a Worldcon a few years back and was showing some pictures of some spiral galaxies like this Hubble image of M81:
Someone in the audience asked if the spiral shape of hurricanes and galaxies were for the same reason. Here’s a picture of Hurricane Floyd from NASA (who takes images of both sorts of objects):
The short answer, which I gave, was “no.” I said “the physics are different.”
Now, spiral patterns are complicated and of different types. Grand design spirals seem to work based on density waves, and another type known as flocculent spirals experience self-propagating star formation which, in combination with their differential rotation, lead to spiral structure. My friend at Case Western, Chris Mihos, has a nice webpage explaining these points. The density wave thing is not that easy to understand, but the analogy that he and I both use in class is that of traffic jams on the highway. Sometimes patterns of car density emerge even though all the cars are moving along in the same direction, and these patterns can persist and travel.
Hurricanes result from low pressure centers in a rotating frame of reference. Air rushing in to fill the low pressure misses because of the rotation. We call the apparent, fictitious force that makes it miss the Coriolis force. This effect is vey different from what’s going on in spiral galaxies. Gas pressure is not important on Galactic scales, at least not for stars that make up the spiral patterns.
An aside about the phrase “the physics are different” and why I was prompted to write this entry. I was having a disagreement with someone on a blog about science fiction fans. My take is that they’re better educated and knowledgeable about science, technology, and future trends. I think this is obvious, but someone else didn’t agree at all. It reminded me of a time with a smart fan after this talk who confronted me at a party to tell me I was wrong. The physics of hurricanes and spiral galaxies are the same. I was flabbergasted. She went on to tell me how she went to MIT and was sure.
Well, all my attempts to explain were quickly rebuffed and my correct perspective on this was rejected. I finally figured out that she was referring to the apparent universality of the laws of physics. The forces and laws are the same here and there, on Earth and deep space. But the dominant forces and the equations describing the spiral patterns are different. There was a fundamental problem with this person’s communication skills. May have been Asberger’s, which isn’t uncommon among scitech people or sf fans either. It was interesting to make the realization about her point later, and just wish I’d made it earlier as I did get irritated.
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I am glad to see that the individual of whom you speak is so well connected. Because as far as I know there is no proof that the laws of physics here are the same as elsewhere. It is supported by our ability to explain well the observables with our current science. It is merely an assumption of the Copernican Revolution which we have no reason to change until we have evidence/reason to suspect otherwise. I guess she knows Galactus personally, and he told this to be a fact.